In a known internal combustion engine with an engine brake device as shown in FIG. 8, during engine braking, with an exhaust brake valve 10 closed, a master piston 2 for a cylinder 7 is actuated by a rocker arm 19. The rocker arm 19, in turn, is actuated by a push rod 1 of another cylinder (not shown) to pressurize oil supplied to oil passage 5 from a rocker shaft bracket through solenoid and control valves 3 and 4. Due to the hydraulic pressure thus produced in line 5, an exhaust valve 8 of the cylinder 7, near its piston's top dead center position, is opened via a slave piston 6 to discharge compressed air from cylinder 7 through exhaust port 9. As a result, the force for pushing down the piston is prevented and a braking force obtained in the compression stroke is effectively utilized with no loss.
In in-line 6-cylindered engines, three oil passages 5 are branched off from a single oil passage provided with a solenoid valve 3 and a control valve 4 is disposed in each of the oil passages 5. This allows the volume of each oil passage 5 to be reduced and enhances responsiveness of the slave piston 6.
An internal combustion engine having a conventional engine brake device described above may be effective for engine braking, but cannot attain recirculation of exhaust gases thereby failing to provide improvement with respect to the problems of NO.sub.x and of white smoke at engine starting. Particularly in a turbo-intercooled engine, exhaust gas recirculation is difficult to carry out.